There's this really great joke that someone told me a million billion years ago, when I was in my mid twenties:
Three men, an Irishman, an Englishman and a Scotsman, get taken captive by some guy who tells them he's gonna use their skin to make boats. He gives them each one last request. I forget what the Irishman and Englishman ask for, though certainly this heavily stereotyped joke made an alcoholic out of the one and probably a glutten out of the other. Sigh. Their requests are beside the point, they fall into typical "last meal" types of requests.
The Scotsman? Asks for a fork and starts piecing his skin all over, screaming (ya gotta say this in a wild Scottish brogue whilst making stabbing gestures towards your body): "Fook you, if ya think you'll be making a boat outta me, ya bloody arsehole!"
I'm somewhere between half to three quarters Scottish and this joke makes me laugh hysterically when I retell it. Plus I love using my very silly fake accents. It's fun!
But here's my actual, serious point: we hurt ourselves (intentionally or not) when we decide to spite others. To do things for the sake of being contrary or not letting someone else get ahead. Being stingy just to be stingy.
And it really is only our own skin that is hurt. The person wanting to use our skin will either patch it or find a replacement. They haven't been hurt. Merely inconvenienced.
So while it's a funny joke, it's not a great way to live, even metaphorically.
Even if you believe there's always someone after your metaphorical skin (the truth of that is a different story altogether), the question to ask yourself is, are you punching holes to spite them, hurting your own self needlessly, or are you practicing generosity?
Generosity isn't gonna save that skin of yours, but neither is forking your own self.
You go down with a lot less pain by practicing generosity. You go down either way, but choosing the path of less-pain might help you bounce back quicker.
Just some food for thought.